Signal Iduna Park as an Energy Asset: What Borussia Dortmund’s Solar Project Shows About Stadium Infrastructure.

Roger Hampel

Image: BVB

In November 2025, Borussia Dortmund completed the installation of what is currently the most powerful photovoltaic system installed on a stadium roof. The project at SIGNAL IDUNA PARK was developed in cooperation with energy group RWE and forms part of a broader sustainability partnership agreed between the two organisations in 2024.

While the installation attracted attention due to its scale, the project is also relevant as an example of how football stadiums are increasingly being treated as energy infrastructure, not only as sports venues.

Scale and Technical Parameters

The photovoltaic system installed on the roof of SIGNAL IDUNA PARK consists of 11,132 solar modules with a total installed capacity exceeding 5 megawatts peak (MWp). According to the club, the system is capable of covering up to approximately 50% of the stadium’s electricity demand under normal operating conditions.

Annual CO₂ savings are estimated at around 1,700 tonnes compared to the previous electricity supply mix. The installation has been certified by the German Record Institute as the largest photovoltaic system ever installed on a stadium roof.

Energy Use in a Stadium Context Signal Iduna Park

Large football stadiums are energy-intensive assets. Electricity demand is driven not only by matchdays, but also by lighting, media infrastructure, catering operations, offices and non-sporting events such as concerts.

In this context, on-site generation reduces reliance on external energy supply and partially mitigates exposure to price volatility in energy markets. However, solar production alone does not automatically align with stadium demand profiles, which often peak in the evening.

Image: BVB

Battery Storage as a Functional Component

To address this imbalance, a battery storage system with a capacity of 3.7 megawatt hours (MWh) is scheduled to be commissioned by early 2026. Once operational, the storage system will allow electricity generated during daylight hours to be used during evening matches and events.

From an operational standpoint, this element is central. Without storage, rooftop solar installations at stadiums primarily reduce baseline consumption rather than matchday load.

Partnership Structure

The project is part of a six-year partnership between Borussia Dortmund and RWE, under which RWE acts as both a commercial partner and an energy solutions provider. Earlier phases of the cooperation included smaller photovoltaic installations at adjacent club facilities.

This structure differs from traditional sponsorship models, as it combines brand association with technical delivery and long-term infrastructure involvement.

Relevance for Other Stadium Operators

SIGNAL IDUNA PARK is an existing stadium rather than a newly built venue designed around sustainability from inception. The project therefore illustrates how legacy infrastructure can be retrofitted to incorporate large-scale renewable energy systems.

For stadium operators facing rising energy costs and increasing regulatory reporting requirements, such installations represent one of the few measures that directly affect operational expenditure while also contributing to emissions reduction targets.